Is it me, or is Wizard's Sidestep one of the single most useful spell for magi who spend any length of time out of the covenant? It's Rego Imaginem level 10, so it's a spell that ANYONE without deficient arts can do, even if all they've done is open their arts. As such and given the massive bonus to protection it gives, I would think it would easily be part of the standard repertoire for any magus from any vaguely outgoing house.
It's just that keen.
Just a thought,
Brian
It nearly falls into the same category as Parma in that once cast you have huge protection for no effort. Very annoying really.
Having said that, it is a surprise that it isn't a spell learned by all...
Wizard's sidestep is useful, but - if used as a precaution - bound to mess up your social interaction with anybody not aware of the spell and its effects. It's a dead giveaway that you are using magic or worse, indeed.
Mastering it for Fast Casting, though, makes it very useful without that drawback, and without the warping resulting from having it continually applied.
But even an unmastered InHe15 Shriek of the Impending Shafts protects you in a similar way against weapons with significant wooden parts, without being noticed if you talk or shake hands.
Kind regards,
Berengar
While I understand why people love this spell, one should also consider playing style. For instance if my Magus goes on an adventure (which is rare) typically he has a target goal. Typically an adventure plays out with my magus sitting in his carriage and giving orders from behind closed doors. The companion do everything. Only when they are stumped or magic is necessary, does my magus actually leave his carriage and contribute to the adventure.
If my Magus had to actually interact with people, he would probably turn invisible and walk about them unseen. He would listen to and guide the companions to interact with people.
In the how to beat an ArchMage thread I said that I'm of the opinion that if you show up for a fight there is a chance you'll die. My magus tries to avoid this by making sure no one ever knows where he is... ever. To be visible and present for a fight or any place where a fight might be, that's foolhardy in his mind. So is he an ecentric Tytalus? Probably. I guess my point is the utilityof this spell is dependant on how your Magus interacts with people. I can see pacifistesque magi with the gentle gift never considering the spell either.
Simply some alternative approaches to mull over.
Magus? Social interaction? 
Don't forget to have the caster's sigil manifest in the image. 